Air-lift pump



July 17, 192s, 1,677,265

. J. o. BovlNG AIR LIFTy PUMP Filed Augf27, 1925 .V fl

wml/raf? am @y JENS ORTEN BOVING, 0F

OFFICE,

WESTMINSTER, ENGLAND.

' .AIR-LIFT PUMP.

Application led August 27, 1925, Serial No.

This invention relates to liquid pumpqs of the air-lift type, i. e. of the type in W .ich the liquid is raised in an uptake or ascenslon pipe by means of compressed air admitted to the pipe at or near its lower end. In such pumps as previously constructed or proposed the compressed air has been lntroduced either axially through a 4single )et from the bottom of the ascension pipe, laterally through a space between adjacent parts of the said pipe, or radially through a number of holes in the pipe. In all these arrangements incomplete aeration. of. the liquid takes place so that a comparatlvely inefficient action is obtained, and the chief object of the present invention is to provide for more complete aeration and a consequent increase of eiiciency. l

According to the present invention the lower part of the ascension pipe is provided with a hollow central member so as to form a space'b'etween it and the pipe and/or an extension of this pipe, the liquid to be lifted owing through this space, and provision is made for admitting compressed air into the said space outwardly through/the said hollow member and inwardly through the pipe and/or its extension. In this manner the air miXes effectively with both the inner and outer layers of the body of the liquid iiowing through the said Aspace and eilicient aeration of the liquid thus takes place. In its simplest form the said hollow member may be in the form of a laterally perforated pipe withits upper end either closed or perforated, this pipe being arranged coaxially within the lower end of the ascension pipe which is formed with perforations or their equivalent, but in the preferred construction the hollow member is of ovoid or similaishape communicating by means of hollow webs with a compressed air casing surrounding the pipe and/or its eX- tension which is formed with perforations whilst the said hollow member is also formed with perforations. The portion of the pipe below the hollow member is'preferably formed with a constriction or throat of such size as to increase the velocity ofthe liquid to at least ten per cent of the spouting velocity corresponding to the immersion head and above this point the annular area of the space between the pipe and the hollow member is increased in correctrelationship to the increase in the volume of the liquid due to the admission of, the com- '52,s35, and in Great Britain August 29, 1924.

pressed air, so that the velocity of liow of the aerated liquid through this space is substantially constant. Above the said hollow member the velocity of the aerated liquid is gradually reduced by making the pipe of progressively increasing cross-sectional area for the required portionof its length. ,v

In order that the said invention may be clearly understood and readily carried into eli'ect, the same will now be described more fully with reference to the accompanying drawing which shows diagrammatically a constructional form of the invention.

A is the ascension pipe and B is the hollow member of ovoid shape connected by hollow webs b, b to the upper part of a pipe C1 having a surrounding casing C so that communication is established by the said hollow webs between the interior of the` said casing and the interior of the hollow member B, compressed air being led to the Acasing C by a pipe c.

forms an extension of the ascension pipe A and dips into the liquid to be raised. The

The said pipe C1' upper part of the hollow member B is perforated as shewn by small holes as is also the upper part of the extension pipe C1. This extension pipe is formedwith a throat or constriction o1 of such a size that, as aforesaid, the velocity of the liquid flowing in this pipe is increased above the constriction to at least ten per cent of the spouting velocity corresponding to the immersion head and this increased velocity is maintained in the annular space between the hollow member B and the upper part of the extension pipe C1 by the gradual increase inthe cross-sectional area. of this annular space, this, increase corresponding approximately to the increase in volume of the liquid due to the admission of air through the holes in the extension pipe C1. This increase is progressive in the annular space between the upper half of the hollow member B and the lower curved part of the ascension pipe A to correspond with the further increase in the volume of the liquid as a result of the additional air passing into the liquid through the holes in the said upper half of the hollow member, so that a constant velocity of iiow is maintained between the constriction c1 vand a point somewhat above the top of the hollow member, beyond which point the pipe A increases in cross-sectional area so as to reduce the velocity of How, the kinetic energy of the aerated liquid being thus transferred into static energy. It will be observed that the cross-sectional area of the throat of the pipe A above the top of the hollow member B is substantially greater than the cross-sectional area of the constriction c1.

Although in the construction shown the holes in the hollow7 member B and those in the extension pipe C1` are not directly opposite each other, they might, by varying the construction, be made directly opposite or approximately so. In any case the compressed air enters the inner and outer layers of the annular body of liquid flowing past the hollow member B so that effective intermingling of the air and liquid is, obtained.

What I claim and desire to secure by Letters Patent of the United States is 1. In a liquid pump of the type 'in which the liquid is raised in an uptake or ascension conduit by means of gas under pressure admitted to this conduit at or near its lower end, the combination with the said conduit of a hollow member disposed within the lower part thereof so as to leave a space between said member and said lower part of the conduit, said member having an in- 4wardly leaning part and said conduit an outwardly leaning part, means for admitting the gas under pressure into said space outwardly through the inwardly leaning part of said hollow member, and means for admitting gas under pressure into said hollowk member, and means for admittin gas under pressure into said space inward y through the outwardly leaning part of the wall of said conduit so that both supplies of gas during their ascent immediately after they enter the liquid pass through the latter at a considerable angle to the direction of flow of the liquid and eicient admixture of the gas and liquid is thereby obtained.

2. In a liquid pum'p of the type in which the liquid is raised in an uptake or ascension pipe by means of gas under pressure admit ted to this ypipe at or near its lower`end, the combination with the said pipe of a hollow member disposed within the lower part thereof so as to leave an annular space between said member and said lower part of the pipe, said member having an inwardly leaning part and said pipe an outwardly leaning part, means for admitting the gas under pressure into said space outwardly through the inwardly leaning part of said hollow member, and means for admitting gas under pressure into said hollow member, and means for admitting gas under pressure into said space inwardly through the outwardly leaning part of the wall of said conduit so that both supplies of gas durin their ascent immediately after they enter t e liquid ass through the latter at a considerable ang e to the direction of flow of the liquid is thereby obtained.

, 3. In a liquid pump of the type in which,

the liquid is raised in an uptake or ascension pipe by means of gas under pressure admitted to this pipe at or near its lower end, the combination with the said pipe of a hollow member disposed within the lower part of said pipe so as to leave an annular space between said member and said lower part, said member having an inwardly leaning part and said pipe an outwardly leaning part, a casing surrounding said lower part, means for supplying gas under pressure to said casing, means for admitting the gas into said annular space outwardly through the inwardly leaning part of said hollow meinber, means for admitting gas under pressure into said hollow member, and means for admittin gas under pressure into said space inwarly through the outwardly leaning part of the wall of said pipe so that both supplies of gas during their'ascent immediately after they enter the liquid pass through the latter at a considerable angle to the dlrectionbf iow of the liquid and eiiieient admixture of the gas and liquid is thereby obtained. y

'4. In a liquid pump of the type in which the li uid is raised in anluptake or ascension pipe y means of gas under pressure ad'- mitted to this pipe at or near its lower end, the combination with the said pipe of al hollow member of substantially ovoid` shape disposed within the lower part of said pipe so as to leave an annular space between said member and said lower art, said member having an inwardly leaning part and said pipe an outwardly leaning part, a casing surrounding said lower parthmeans for supplyinfr as under ressure to said casin means for admitting the gas from said casin into said annular space outwardly throught e inwardly leaning part of said hollow member, means foradmitting gas under pressure into said hollow member, and means for ad mitting gas under pressure into said space inwardly through the outwardly leaning part of the wall of said pipe so that both supplies of gas during their ascent immediately after they enter the liquid pass through the latter at a considerable angle to the direction of flow of the liquid and efiicient admixture of the gas and liquid is thereby obtained.

5. In a liquid pump of the type in which the liquid is raised in an uptake or4 ascension pipe by means of gas under pressure ad'- 1 mitted to this pipe at or near its lower end, the combination with the said pipe of a hollow member of substantially ovoid` shape disposed within the lower part of said pipe so as to leave an annular space between said member and said lower part, said member having an inwardly leaning part and said through the inwardly' leaning part of said extension means for admitting gas under pressure into said hollow member, and means for admitting gas under pressure into said space inwardly through the outwardly leaning part of the lwall of said pipe so that both supplies of gas during their as`ent immediately after they enter the liquid, pass through the latter at a considerable angle to the direction of flow of the liquid,` and eilicient admixture of the gas and liquid is thereby obtained.

6. In a liquid pump of the type in which the liquid is raised in an uptake or ascension conduit by means of air under pressure admitted to -this conduit at or near its lower end, the combination with the elements claimed in claim 1, of a portion of the conduit below the hollow member formed with a eonstrictionor throat of such size as to increase the velocity of the liquid to at least ten per cent of the spouting velocity corresponding to the immersion head and above this point the annular area of the space between the conduit and the hollow member is in"reased in correct relationship to the increase in the volume of `the liquid due to to the admission of the compressed air, so that the velocity of flow of the aerated liquid through this space remains substantially constant.

7. In a liquid pump of the type in which the liquid is raised in an uptake or ascension pipe by means of air under pressure admitted to this pipe at or near its lower end, the combination with the elements claimed in claim 4, of'a portion of the pipe below the hollow member formed with a constriction or throat of such size as to increase the velocity of the liquid to at least ten per cent -of the" spouting velocity corresponding to the immersion head and above this point the annular area of the space between the pipe and the hollow member is increased in correct relationship to the increase in the volume of the liquid due to the admission of the'fompressed air, so that the velocity of flow of the aerated liquid through this space remains substantially constant.

8. In a liquid pump of the type in which the liquid is raised in an uptake or ascension pipe by means of air under pressure admitted to this pipe at or near its lower end, the combination with the elements claimed in claim 4, of a portion of the ascension pipe above the level of the top of the hollow member made of progressively increasing crosssectional area so as to gradually reduce the velocity of the aerated liquid.

9. In a liquid pump of the type in which the liquid is raised in an uptake or ascension pipe by means of gas under pressure admit-ted to this pipe at or near its lower end, the combination with the said pipe of a hollow member of substantially ovoid shape disposed within the lower part of said pipe so as to leave an annular space between said member and said lower part, perforations in the upper part of said hollow member for admitting the gas under pressure outwardly into said annular space, said perforations being opposite an unperforated portion of the lower part of the pipe and the lower part of ysaid hollow member being unperforated, perforations in the lower part of said pipe for admitting the gas under pressure inwardly into said annular space, the latter perforat-ions being opposite the lower unperiorated portion of sa1d hollow member.

10. In a liquid pump of the type in which the liquid is raised in an uptake or ascension pipe by means of gas under pressure admitted to this pipe at or near its lower end, the combination with the said pipe of a hollow member of substantially ovoid shape provided with an inwardly leaning part and disposed within the lower part of said pipe so as to leave an annular space between said member and said lower part, said lower part being shaped with an outwardly leaning portion so as to conform substantially with the ovoid shape of the hollow member, perforations in the inwardly leaning -upper part of said hollow member for admitting the gas under pressure outwardly into said annular space, said peri'orations being opposite an unperforated portion of the lower part of the said pipe and the lower part of the said hollow member being unperforated, and perforations in the outwardly leaning lower part of said pipe for admitting the gas under pressure inwardly into, said annular space, the latter perforations being opposite the lower unperforated portion of the said hollow member.

J ENS ORTEN BOVING. 

